Noise compensated audio volume control system for spas and hot tubs

ABSTRACT

A system for automatically adjusting the audio level in response to spa jet pump and air blower settings in an audio system mounted in a spa or hot tub. A preferred embodiment includes a spa pump/blower sensor apparatus, and an electronic controller circuit which interfaces to the audio system and the spa pump/blower sensors.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority of Provisional application Ser.No. 60/480,049, filed on Jun. 20, 2003.

FIELD OF THE INVENTION

[0002] This invention relates generally to the field of electricaldevices, and more particularly to an apparatus for compensating for pumpnoise in an integrated spa audio system.

BACKGROUND OF THE INVENTION

[0003] In a typical spa or hot tub, the water circulating pumps and airblowers create a significant amount of noise when they are activated.This noise level varies as a function of how many, and which of theavailable pumps/blowers, are operating at any one time. It is becomingincreasingly popular to outfit the spa unit with an integrated audiosystem. This system typically consists of two or more loudspeakersmounted at or above the plane of the water, and an audio head unit toprovide source material and amplification for the audio system. If thespa occupant is listening to a program source at a relatively low level,and one or more pumps/blowers are switched on, the perception of theloudness of the music signal is dramatically altered. In the mostextreme case the music can be masked entirely. Conversely, if a desiredmusic level is selected while the pumps/blowers are active, aftershutting off the pumps/blowers, the music will seem much too loud.

[0004] Historically there has been no way to automatically compensatefor this noise masking effect. The operator would have to manuallyadjust the audio level in order to compensate for the masking effect ofthe pump noise.

[0005] A further challenge lies in the detection of spa pump operation.Most spa controllers do not provide any easily accessible logic pins foran external circuit to monitor pump status. Pump motors are typicallyhigh voltage and high current devices. There are very strict regulationsrelating to electrical devices in the spa environment, especiallydevices which are in contact with high voltage circuits.

[0006] Audio system head units that are commonly used in spa audiosystems lack a means for adjusting the audio signal level by a remotecircuit. This lack of interface prevents the conventional componentsfrom being able to be used in conjunction with a noise compensationcircuit.

SUMMARY OF THE INVENTION

[0007] The primary object of the invention is to provide a means forautomatically adjusting the sound level of an audio system in spa andhot tub applications.

[0008] Another object of the invention is to be able to detect the spapump/blower status without direct electrical connection to the pumpwires or controlling electronics.

[0009] Other objects and advantages of the present invention will becomeapparent from the following descriptions, taken in connection with theaccompanying drawings, wherein, by way of illustration and example, anembodiment of the present invention is disclosed.

[0010] This invention features an apparatus where the operation of thevarious pumps and blowers is sensed, the average ambient noise levelcontributed by them is determined, the sound level of the audio systemis determined, and said sound level is adjusted such that the listenerperceives a consistent sound level from the audio system regardless ofchanging pump/blower settings.

[0011] The drawings constitute a part of this specification and includeexemplary embodiments to the invention, which may be embodied in variousforms. It is to be understood that in some instances various aspect ofthe invention may be shown exaggerated or enlarged to facilitate anunderstanding of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a block diagram of the primary components of thepreferred embodiment of the system of the invention;

[0013]FIG. 1A is a more detailed block diagram of the noise compensationprocessor of FIG. 1;

[0014]FIG. 2 is a more diagram of the preferred inductive pick-upmethodology of the invention;

[0015]FIG. 3 is a block diagram of an alternate embodiment using awireless interface to a conventional head unit; and

[0016]FIG. 3A is a more detailed block diagram of the noise compensationprocessor of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Detailed descriptions of the preferred embodiments are providedherein. It is to be understood, however, that the present invention maybe embodied in various forms. Therefore, specific details disclosedherein are not to be interpreted as limiting, but rather as a basis forthe claims and as a representative basis for teaching one skilled in theart to employ the present invention in virtually any appropriatelydetailed system, structure or manner.

[0018] Turning to FIG. 1 there is shown a block diagram of the primarycomponents relating to a preferred embodiment of the invention.Inductive pick-up sensors 5 are mounted on the various high currentcircuits for the pumps/blowers. Sensors 5 determine when a pump orblower circuit is passing current to the pump/blower motor. A noisecompensation processor 1 is connected to audio head unit 4 via aninterface bus 2. The head unit interface bus 2 presents the noisecompensation processor 1 with internal audio signals such that thesesignals can be monitored and modified to achieve the goals of theinvention.

[0019]FIG. 1A is detailed block diagram of the preferred embodiment ofthe noise compensation processor for the invention. Pump detectioncircuit 20 receives signals from pump sensors 21 and interfaces tomicroprocessor 19, allowing the system to determine which, if any of thespa pump circuits are operating. The audio input signal 15 is fed toaudio signal level detection circuit 18 where the average audio level isdetermined, and sent to microprocessor 19. Using the pump status andsignal level information, microprocessor 19 calculates a noisecoefficient based on previously determined pump/blower noise data. Usingalgorithms and look-up tables, a gain adjustment is calculated andapplied to variable gain element 17, which sends the processed audiooutput 16 to the head unit. Because the audio signal is constantlymonitored, the administered level adjustment is based on the actualaudio level, not the volume setting. This approach has the benefit thatit provides not only an overall level adjustment of the audio signal,but also provides a dynamic range compression of the audio signal.Dynamic range compression is important in noisy environments where theaudio program material sound level varies greatly. This is commonlyfound in classical music with wide dynamics, or a movie soundtrack wherea loud chase scene might be followed by quiet dialog. The process isconstantly repeated in order to maintain an optimal audio signal topump/blower noise relationship. In another embodiment, audio frequencyequalization may also be applied to the audio signal as a function ofspa noise. This can have the advantage of recovering specificfrequencies that the spa pump generated noise might be masking.

[0020]FIG. 2 is a more detailed view of one manner of detecting pumpoperation. Spa controller board 7 contains the logic and switchingrelays for the pumps and blowers. Inductive pick-up clips 9 are clippedto each of the noise producing pump/blower winding circuits 8. Somepumps or blowers may have multiple speeds, for example separate low andhigh-speed circuits. In this case, by employing sensors on each of thedrive circuits, the speed of operation can also be determined, and theaudio output level adjusted accordingly. Wiring harness 10 carries thesignals back to the noise compensation processor for filtering anddetection.

[0021]FIG. 3 shows an alternate embodiment where audio head unit 11 isof conventional design, equipped with a wireless receiver 12. In thisembodiment, noise compensation processor 14 is configured to output adata stream compatible with the audio head unit's wireless controlinput. The signal is sent to the audio head unit via wirelesstransmitter 13.

[0022]FIG. 3A is a more detailed block diagram of this alternateembodiment. Pump and audio level detection are calculated in the samemanner as described for FIG. 1A. In this case audio input 22 wouldconnect directly to a loudspeaker output on the head unit. Aftercalculating the gain adjustment, microprocessor 25 generates a volumecontrol code and sends a bit stream to wireless transmitter 23, whichtransmits the signal to the audio head unit, thereby adjusting the audiolevel. Means for transmission is most commonly through Infra-red (IR)signal, although other mechanisms could be used, including RF, andserial data through a wired connection.

[0023] While the invention has been described in connection with apreferred embodiment, it is not intended to limit the scope of theinvention to the particular form set forth, but on the contrary, it isintended to cover such alternatives, modifications, and equivalents asmay be included within the spirit and scope of the invention as definedby the appended claims.

What is claimed is:
 1. A noise-compensated audio control system for spasor hot tubs that have an audio system comprising an audio head unit thatsend audio signals to one or more loudspeakers, and that have pumpsand/or blowers, comprising: means for sensing when a pump or blower isoperating; and means, responsive to the means for sensing, forautomatically adjusting the audio output level of the audio system, toincrease the audio level when the noise increases, and decrease theaudio level when the noise decreases.
 2. The control system of claim 1,further including means for determining the current audio output levelof the audio system.
 3. The control system of claim 2, wherein the audiooutput adjustment means is further responsive to the current audiooutput level, so that the current audio output level can be adjusted upor down as necessary.
 4. The control system of claim 2, furthercomprising means for causing the audio signal to undergo dynamic rangecompression.
 5. The control system of claim 2, further comprising meansfor causing the audio signal to undergo frequency equalization as afunction of noise level.
 6. The control system of claim 1, wherein thesensing of the operation of the pump or blower is conducted withoutdirect electrical contact to the spa or hot tub electrical wiring. 7.The control system of claim 6, wherein the sensing of the operation ofthe pump or blower is conducted with inductive sensors.
 8. The controlsystem of claim 1, wherein the means for automatically adjusting theaudio output level is accomplished by means of sending a wirelesscontrol signal to the audio head unit.
 9. The control system of claim 2,wherein the means for automatically adjusting comprises amicroprocessor.
 10. The control system of claim 9, wherein the means forautomatically adjusting further comprises a variable gain elementresponsive to the microprocessor.
 11. The control system of claim 10,wherein the variable gain element sends an audio output signal to thehead unit.
 12. The control system of claim 11, wherein the means fordetermining the current audio output level comprises an audio signallevel detector connected to the audio head unit.
 13. The control systemof claim 13, wherein the audio signal level detector is also connectedto the microprocessor, so that the microprocessor can determine thecurrent audio output level.
 14. A noise-compensated audio control systemfor spas or hot tubs that have an audio system comprising an audio headunit that send audio signals to one or more loudspeakers, and that havepumps and/or blowers, comprising: means for sensing when a pump orblower is operating, wherein the sensing of the operation of the pump orblower is conducted without direct electrical contact to the spa or hottub electrical wiring; means for determining the current audio outputlevel of the audio system; and means, responsive to the means forsensing, for automatically adjusting the audio output level of the audiosystem, to increase the audio level when the noise increases, anddecrease the audio level when the noise decreases, wherein the audiooutput adjustment means is further responsive to the current audiooutput level, so that the current audio output level can be adjusted upor down as necessary, wherein the means for automatically adjustingcomprises a microprocessor, and wherein the means for automaticallyadjusting further comprises a variable gain element responsive to themicroprocessor, wherein the variable gain element sends an audio outputsignal to the head unit, and wherein the means for determining thecurrent audio output level comprises an audio signal level detectorconnected to the audio head unit and to the microprocessor, so that themicroprocessor can determine the current audio output level.